In recent years Flow Solutions has focussed considerable
effort in the area of static and dynamic aeroelasticity, working in
close collaboration with MSC.Software to provide coupled
aero-structural solutions.
Static Aeroleasticity
- Non-linear analysis of the aero-structural coupled problem
- "Free flight" aerodynamic loads, with stuctural deformation
- Splining procedure between aero and structural mesh
- Iterative analysis with rapid convergence
- Full NEWPAN aerodynamics- true wetted surface of complex configurations
More information on the coupled
static aeroelastic process is available here.
Trim Solver
- Fully automated capability for controller trim for level flight
- Iterative NEWPAN-MSC.Nastran™ coupling
- An enhanced capability with direct communication to the
MSC.Nastran™ database is planned
Dynamic Aeroelasticity
- Directly coupled USNEWPAN-MSC.Nastran™
flutter analysis
- Dynamic solutions about the fully trimmed, static aeroelastically
deformed, configuration
- Full NEWPAN aerodynamics- true wetted surface, i.e. including
all incidence and thickness effects, for complex configurations
- Direct communication of NEWPAN/USNEWPAN aerodynamics to the
MSC.Nastran™ database
- Maneuver simulations, eg pull up
- Gust analysis (in progress)
- Aerodynamic solutions for any combination of incidence, (subsonic)
Mach number, and reduced frequency parameter
- A fast and practical capability with much higher fidelity
aerodynamics than DLM
More information on USNEWPAN
based flutter analysis is available here.
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As an example of the powerful capability provided by coupled
NEWPAN-MSC.Nastran™, Flow Solutions and MSC.Software have prepared
an aeroelastic analysis of a complete light airplane. This
includes full, detailed modelling of the structure, including
all controllers (rudder, elevators, ailerons) and complete
wetted area modelling of all aerodynamic surfaces. Such a model
allows a detailed investigation of both static and dynamic aeroelastic
effects, including checks for flutter.
Presented here are the results, at a 200km/h, 1g point in the flight envelope,
for the structural mode determined
to be critical - namely fuselage bending/torsion. The instantaneous surface
pressure coefficients (i.e. steady mean plus unsteady perturbation),
are shown along with the accompanying structural deflections
and aerodynamic force vectors.
The unsteady analysis was performed after a full static
aeroelastic analysis to establish the trimmed and deformed mean
configuration at the specific point in the flight envelope.
Using this starting point, USNEWPAN was run in MSC.Nastran™
coupled mode. This provides the results for the steady flow, plus the
unsteady aerodynamic perturbations, in the frequency domain, in matrix
form, for the requested Mach numbers and reduced frequency parameters.
The aerodynamic results are communicated directly into the MSC.Nastran™
database. This enables the complete range of flutter postprocessing
tools to be used, for instance.
The aerodynamic model was created in the GEMS preprocessor as a
5839 panel full model. NEWPAN/USNEWPAN is a fast and practical
tool, able to populate the aeroelastic database with dozens,
or hundreds, of aerodynamic datasets in a realistic timescale.
For this complete model, here is an example of the runtime:
Pentium P4 3.2GHz single CPU desktop PC
5839 panels full light aircraft
Incompressible, steady, 5 wake relaxations, PLUS unsteady
frequency domain, 1 reduced frequency, 6 modes: 5.1 minutes
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